The present invention relates to a method and a device for the preservation of packaged beverage preparing products, i.e. to a method and a device for preserving the aromas and organoleptic characteristics of a product in a capsule, cartridge, pod or similar disposable single-dose packaging means suitable for preparing beverages from automatic machines.
The use of disposable single-use plastic or paper packages such as cartridges, pods, capsules and the like, containing a product for preparing a beverage in an automatic machine, is known and widespread. The products for preparing beverages are in general ground or soluble coffee, tea, powder milk, herbal preparations and powder products for soups; these products are located within a container that is pod, capsule or cartridge that is intended to be inserted in a beverage preparing machine that brews or solubilize the product out of its container into a cup or similar beverage container. For clarity and conciseness, in the following description the word “capsules” will be used to identify also cartridges, pods and similar containers.
The use of these packages results in several advantages e.g. the tidiness of operation, the ability to achieve consistently the required quality of the end product (a.k.a. “quality in the cup”) and a greater preservation from oxidation of the individual package with respect to the same product in a “bulk” container. In fact, coffee in a container, once open, will inevitably come into contact with ambient air; even if the container is re-sealed, contact with ambient air will be renovated with every withdrawal of a coffee dose from the container.
Recently, sealed packages became known. These packages are e.g. capsules sealed on both inlet and outlet: WO2006030461 in the name of the present applicant discloses such a capsule, that will be opened only when it has to be used for preparing the relevant beverage.
Packages that are not sealed, e.g. filter paper pods or traditional, open, plastic cartridges, are usually housed in an external container that is sealed to provide the required barrier to ambient air. It is quite important for both sealed and non-sealed capsules that ambient air and oxygen do not come into contact with the beverage product, e.g. ground coffee, especially because the time between packaging and consumption of the capsule can be relatively long.
It has been found that, when plastic packaging material is used, there always is a partial permeability of the sealing material to the ambient air oxidants. Aluminium laminated sheets provide a material that is substantially impermeable to oxygen; however, oxygen is usually found in capsules or containers, even in those containers that were packaged in an inert atmosphere, such as a nitrogen only atmosphere in a filling and packaging station under air-tight conditions.
US-A-20060144811 discloses a device for removing oxygen from a container of beverages or food that provides an oxygen absorber composition and an oxygen detector circuit on the inner wall of the closure member of the beverage or food container. The oxygen absorber composition is held in place, on the underside of the cap or closure member, by a cover layer of gas permeable film that prevents contact between the absorbent and the contents of the container; the oxygen detector generates a signal that provides an indication of the presence or absence of oxygen in the container. This device cannot be used in the present invention field because it requires a rigid container provided with a lid or closure member.
EP 0633013 discloses a method and a container for storing and stabilizing a powdered medicine containing bicarbonate. The medicine is packaged in a first container permeable to gas and water, that is housed in a second container non-permeable to gas and water. The second container is preferably filled with carbon dioxide and an oxygen scavenger is housed therein. This device relates to a different (i.e. medical) field and is designed to be used with single packages only, i.e. with packages wherein the second container is containing a single dose only. Such a package is of no use in the invention field because the medicine has to be removed from the first inner container and used immediately after opening the second, outer, container.
JP 2003 285876 (TOKAN KOGYO) discloses a package for meat and fish wherein the product is packaged in a first container impermeable to oxygen and wherein the first container is housed in a second container (also impermeable to oxygen) with an oxygen absorbing element. The aim and the teaching of this document is to avoid any chance of oxygen penetrating in the first container.